Therapeutic Effect of Niclosamide versus Triamcinolone on Rabbit Ear Model of Hypertrophic Scar

Hypertrophic scar is a pathological condition stemming from an aberrant wound healing response, marked by excessive collagen deposition and fibroblast proliferation. Triamcinolone acetonide, a corticosteroid drug, has long been regarded as the gold standard for the non-surgical treatment of hypertrophic scars. Niclosamide, a repurposed anti-parasitic drug, has gained growing interest for its potent anti-fibrotic and anti-inflammatory effects via modulation of diverse signaling mechanisms, beyond its traditional use against helminthic infections.

This study aimed to assess the therapeutic effects of niclosamide and compare it to the standard steroid triamcinolone acetonide in an established rabbit ear model of hypertrophic scarring.

Forty healthy male rabbits were separated into 4 groups (n=10). The healthy control group received no treatment. The sham (induction) group underwent hypertrophic scar induction and received only vehicle-based gel. The remaining groups were given 0.1% triamcinolone acetonide or 2% niclosamide for 21 days after scar induction. Wound tissues were studied using immunohistochemistry and histology approaches.

Niclosamide substantially improved inflammatory scores, fibroblast counts, scar elevation index, wound size, and scar height when compared to the sham group (induction). Additionally, niclosamide dramatically reduced immunohistochemistry scores for TGF-β1 and collagen III. While triamcinolone lowered fibroblast count, niclosamide was more effective in reducing wound size and scar height.

Niclosamide considerably improved the histological and immunohistochemical elements in hypertrophic scars, indicating a potential therapeutic effect similar to that of triamcinolone acetonide.

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